This invention relates to a coke oven built in flat-type construction, i.e. a so-called non-recovery or heat-recovery coke oven consisting of at least one measuring device to measure the concentration of gas constituents in the coke oven chamber, coke oven sole and/or waste gas channel, and wherein the optimal supply of primary and/or secondary air is determined and controlled via a process computer on the basis of this data. This invention also covers a cokemaking process utilizing a coke oven of this type.
Heating of heat-recovery ovens is usually performed by combustion of gas evolving on cokemaking and/or by burning the portions of light-volatile matter of coal to be carbonized. Combustion is controlled in such a manner that part of the gas above the coal charge burns off with primary air in the oven chamber. This partly burnt gas is fed through gas channels that are also designated as “downcomers” to the oven sole and completely burnt there by the addition of further combustion air, which is called secondary air.
In this way, heat is directly supplied from the top and indirectly from the bottom to the coal charge, thus taking a positive impact on the coking rate and, thereby, on the performance rate of coke ovens. To execute the method it is required to exactly rate and variably control the supplied primary and secondary air throughout the coking time that may take up to 96 hours. Heat-recovery and non-recovery coke ovens in flat-type construction are widely described in prior art disclosures. For example, reference is taken to U.S. Pat. No. 4,344,820, U.S. Pat. No. 4,287,024, U.S. Pat. No. 5,114,542, GB 1 555 400 or CA 2 052 177 C.
According to the conventional state of the art in technology, primary air is sucked in from the atmosphere through ports in the doors. Secondary air is sucked in through ports near to ground and conducted through channels into the heating flues which mainly extend horizontally under the coke oven chamber. The ports for primary and secondary air are either opened permanently or provided with flaps designed to adjust the amount of air to be aspirated.
As the coke oven batteries are very extensive, and since usually a very high temperature prevails therein and because a serious development of dust is encountered, only manually adjustable venting flaps are disclosed in prior art technology. U.S. Pat. No. 5,928,476 describes such a coke oven battery, wherein three manually operable ports are provided in each coke oven door, in which or in front of which one plate or disk each adapted to the port cross-section and supported at a central axle is arranged. These port flaps can be varied in their position manually through levers.
The German patent DE102005055483.0-24 of the applicant discloses a central adjusting element that permits a continuous control of primary and secondary air.
In practice, however, it became evident that varying coal qualities due to different coal crushing degrees, coal moisture or inert portions, etc. were difficult to master with prior art coke ovens and that unnecessarily long coking times had to be planned to attain high coke quality.